Runic Games CEO Max Schaefer, for instance, tells us that while it's been almost three years since his studio launched Torchlight, Valve's Steam promotions have helped the game maintain healthy sales to this very day.

"We find that we get several thousand percent increases in units and revenue on the days of the Steam sales, and unit sales are usually about double the normal for a few weeks after the sales are over," he says.

This year's Summer Sale (which ended July 22) was particularly noteworthy for Runic, as it helped Torchlight hit its second biggest day ever in terms of overall unit sales — not bad for a game that came out in October 2009.